Impact-machine.



W. L. SMITH.

IMPACT MACHINE. APPLICATION FILED 001'. 25, 1910.

Patented Feb. 9, 191 5.

2 SHEETS-SHEET 1.

LW ENTOR. m

W. L. SMITH.

IMPACT MACHINE.

APPLICATION FILED omzs, 1910.

1,12%535 Patented Feb. 9, 1915 2 SHEETSSHEET 2.

LYVEYTOR.

I V] T N E SSZZS WILLIAM L. SMITH, OF CHICAGO, ILLINOIS.

IMPACT-MACHINE.

Specification of Iietters Patent.

Patented m. e, was,

Application filed October 25, 1910. Serial No. 588,961.

To all whom it may concern:

Be it known that 1, WILLIAM L. ,Smrrn, citizen of the United States ofAmerica, residing at Chicago, in the county of Cook and State ofIllinois, have inventedcertam new and useful Improvements 1n Impact-Machines, of which the following is a specification.

My invention relates to new and useful improvements in impact machmes ofthe class in which a reciprocatory element 1s forcibly brought inengagement with a dullsteel, riveting-set or other tool which 1s lmgitudinally-movably held in the forward end of the housing in which thesaid element has its movement.

One object of the invention resides in the provision of a hammer ofspherical or partly spherical form which during its reciprocatingmovement within acylmdrrcal guiding wall will engage therewlth onlyalong a circumferential line, whereby friction 13 reduced to a minimum,and which will engage the end of a tool supported in axial almement withthe said guiding member, at but one point in which the entire force of1ts impact is concentrated.

Another object of the invention, of equal importance, resides in theprovision of an operating mechanism in which slmpllclty of constructionis combined with practicability in use, by which the impact of thehammer upon the tool is rendered effective to a high degree without theemployment of an air-compressor, steam-generator or other source ofmotive fluid, which performs its function with the minimum of friction,and in which the reactive forces of the reciproeating element areabsorbed to destroy the1r detrimental efi'ect upon the supporting andoperating parts of the machine.

An embodiment of my invention in its simplest form, is illustrated theaccompanying drawings, in the various v ews of which like parts are smilarly designated and in which Figures 1 and 2 represent longitudinalsections of my improved machine with the hammer in its extremepositions, F 1g. 3, a longitudinal section taken along the line 3-3Figs. 1 and 2, with the hammer in an intermediate position and showing amodified construction of the cylinder, and Figs. 4 and 5, fragmentaryviews ofthe plston rod comprised in the construction, showing mgldifiedforms of the hammer at its outer en Referring to the drawings bynumerical reference characters, 2 designates a housing which in the formshown, consists of a circular crank-case 3 and a cylindrical trunk 4whose axes extend at right angles to each other. The case 3 is providedwith an axial bearing 5 for the support of a rotatory shaft 6 which atits inner extremity, carries a crank 7. The latter is composed of acrank arm 7 and a thereto diametrically opposed counterpoise 7 whichserves to render its movement equable, and a ball-bearing 8 appliedwithin the bearing 5, aids in reducing the friction between the movingand stationary parts.

An air-cylinder 9 is pivotally secured at the end of the crank arm 7 bymeans of a wrist 9 which is preferably formed integral with thecircumferential wall of the cylinder, at right angles to itslongitudinal axis. The wrist 9 is held against longitudinal displacementby a cap 10 which, being screwed into a threaded bore in its outer end,engages the inner surface of the crank-arm, and the cylinder 9 isprovided with a stuffing box 9 and a gland 12 which is elongated for thebetter support and guidance of the rod 13 -of a piston 13 which ismovably fitted within the cylinder in fluid tight engagement with theinterior surface thereof. The rod 13 which constitutes the pitman bymeans of which the rotatory movement of-" the crank .7 is converted intoa reciprocating movement of the impact-element, is formed at itsopposite end, with a spherical head 14 which is slidably fitted in thecylindrical trunk 4 of the housing, to impingeupon the end of a tooldisposed in axial a'linement therewith. The tool, which in the drawingsis indicated by the numeral 15, has an angular shank 15 which islongitudinally movably disposed in a correspondingly formed opening in achuck 16, which is rotatably mounted upon the circumferential surface ofthe trunk 4 and which is provided with a handle 17 bymeans of which itmay be moved to impart a partial rotation to the tool, while the machineis in operation.

A combined thrust-washer and bearing composed of fiber or other suitablematerial to supply the air to the drill hole or to the is interposedbetween the end of the member 4 of the casing and the inner surface ofthe chuck and the latter is provided with a hand-valve 19 which, when inits normal position, partly closes an opening 20, provided to establishcommunication between the interior of the trunk and the atmosphere.

A nipple 21, the passage through which is controlled by a check-valve 21isscrewed into an opening in the forward end of the chuck, whichcommunicates with its interior, and it is adapted for the attachment ofa flexible conduit 22 by means of which the air displaced in front ofthe hammer 14 may be conveyed into the drill-hole to dislodge and removethe cuttings contained therein.

It will be understood that in case a hollow drill-steel is employed, theconduit 22 may be dispensed with, and that the valve 19 is'closed onlywhen it is required conduit 22 at more than ordinary pressure.

In the operation of my improved machine, the shaft is connected by anysuitable means, withan electro-motor or other device for producing ortransmitting mechanical energy and its rotatory movement is, by means ofthe crank 7, converted into a combined circular and oscillatory motionof the cylinder 9, which for reasons hereinafter to be explained, isprovided at a point approximately midway between its ends, with anair-hole 9.. When the hammer 14 is in its rearmost position, as isillustrated in Fig. 1 of the drawings, and the shaft 6 rotates in thedirection of the arrow in Fig; 3, the piston is at the end of itsrearward stroke and the air in the rear end of the cylinder is inconsequence, compressed to the maximum. During the subsequent circularmovement of the cylinder toward the forward dead center of the crank,this body of compressed air, will by its expansive action, acceleratethe piston with the result that it travels forward at a rate of speedexceeding that of the crank-shaft and that when the parts approach theposition shown in Fig.2of the drawings, the hammer 14 is, inconsequence, brought forcibly in contact with the end of the drill-shankprojecting into the trunk 4. When'the crank is near the forward cyclechange, the space in the cylinder back of the piston is in communicationwith the exhaust opening, while the body of air in the forward part ofthe cylinder is under compression and serves together with the recoil ofimpact, to start the piston on its rearward movement, thereby assistingthe crank in its motion after the exhaust opening is closed by thepiston. The alternate compression of the bodies of air at opposite sidesof the piston serves in addition to the functions hereinabove explained,to provide the numeral 2.

cushions which by absorption of the reactive forces, relieve the partsof the machine from detrimental shocks.

' By the provision of the air-hole 9, un-

equal distribution of the air at opposite sides of the piston, byleakage or other causes, will be averted, and the latter will at alltimes be properly balanced, i. c. it will be returned to its properposition at the end direction of its movement, is compressed while,when. the piston has passed the center of the cylinder, it will admitair at the opposite side thereof.

It will be observed that during the rapid rotatory motion of the crank,the centrifugal force of the cylinder 9 at-its extreme end, becomes animportant factor in rendering the impact of the hammer upon the toolforceful and effective, and that the spherical shape of the hammer,besides reducing its frictional contact with the guiding surface to theminimum, will serve to concentrate the forces which produce its impact,in the single point atwhich it comes in contact with the extremity ofthe tool.

The hammer 26, as shown in Fig. 4, is pear-shaped in form, its partlyspherical portion 26 being designed to contact with the guiding surfaceof the housing along a circumferental 'line, while its point 26 may bespherical-to tangentially engage the tool. In the form illustrated inFig. 5, the hammer 27 is cylindrical to move between parallel guidingsurfaces, and the projection 27 at its forward end, is made spherical toengage the tool as hereinbefore described.

It will be observed that in the construction shown in Figs. 1 to 4inclusive, the hammer together with the piston and the piston rod, arefree to rotate about their common axis, thus equalizing the wear of theguiding surface in the trunk 4, the gland 12, the stufling box, theinterior surface of the cylinder and the therewith engaging parts of thepiston.

The machine in its simplest form, as shown in the drawings, is designedto be held in the hand of the operator, it being to this end, providedas usual,'with a handle the shank of which has been designated by It isobvious, however. that by immaterial changes in the con struction of thedevice as shown, it may be used in connection with a column or othersupport, that it may be applied to Liz-536st any of the mechanicalfeeding devices at present in common use, and that the rotatory motionof the tool, whichin the form shown, is effected by manipulation of thehandle 17, may be automatically accomplished by mechanical means, which,not forming part of the present invention, have not been shown in thedrawings.

Having thus described my invention what I claim and desire to secure byLetters-Patent is 1. In an impact machine, a casing having a fixedcylindrical guiding surface, a spherical impact-element slidably fittedtherein, and means for imparting a combined reciprocating andoscillatory movement to said element, said element bein adapted toengage a tool held in the path 0 its reciprocating movement.

2. In an impact machine, a casing having a fixed cylindrical guidingsurface, a rotary crank, a cylinder pivotally connected with the latter,a piston movably fitted in the cylinder, and a spherical impact elementrigidly connected with said piston, slidably fitted in said guidingsurface and adapted to engage a tool held in the path of its movementwith the said piston.

3. In an impact machine, a casing having a fixed rectilinear guidingsurface, a rotary crank, a cylinder pivotally connected therewith, apiston movably fitted in said cylinder, and an impact element of firmmaterial in rigid connection with said piston and in linear contact withsaid surface,

so as to be capable of oscillation while being impelled along saidsurface by movement of said crank.

4. In an impact machine, a casing having a fixed rectilinear guidingsurface, an impact element of firm material in linear contact with saidsurface and capable of oscillation while moving along the same, and

means for imparting to said element a combined reciprocating andoscillating movement.-

5. In combination, an' oscillating cylinder having a movement in acircular path, apiston slidably fitted in said cylinder, an impactelement in rigid connection with said piston, and rigid means forguiding said element for rectilinear reciprocation, the said elementbeing adapted to oscillate while moving along said guiding means.

6. In an impact machine, a casing having a fixed rectilinear guidingsurface, and a spherical impact element movable along said surface toengage a tool held in its path, and means for imparting a combinedreciprocating and oscillatory movement to said element.

In testimony whereof I aflix my signature in presence of two witnesses.

CHARLES T. ARKINS, R. F.. DENNIS.

